xref: /OK3568_Linux_fs/kernel/arch/m68k/mac/baboon.c (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun  * Baboon Custom IC Management
4*4882a593Smuzhiyun  *
5*4882a593Smuzhiyun  * The Baboon custom IC controls the IDE, PCMCIA and media bay on the
6*4882a593Smuzhiyun  * PowerBook 190. It multiplexes multiple interrupt sources onto the
7*4882a593Smuzhiyun  * Nubus slot $C interrupt.
8*4882a593Smuzhiyun  */
9*4882a593Smuzhiyun 
10*4882a593Smuzhiyun #include <linux/types.h>
11*4882a593Smuzhiyun #include <linux/kernel.h>
12*4882a593Smuzhiyun #include <linux/irq.h>
13*4882a593Smuzhiyun 
14*4882a593Smuzhiyun #include <asm/macintosh.h>
15*4882a593Smuzhiyun #include <asm/macints.h>
16*4882a593Smuzhiyun #include <asm/mac_baboon.h>
17*4882a593Smuzhiyun 
18*4882a593Smuzhiyun int baboon_present;
19*4882a593Smuzhiyun static volatile struct baboon *baboon;
20*4882a593Smuzhiyun 
21*4882a593Smuzhiyun /*
22*4882a593Smuzhiyun  * Baboon initialization.
23*4882a593Smuzhiyun  */
24*4882a593Smuzhiyun 
baboon_init(void)25*4882a593Smuzhiyun void __init baboon_init(void)
26*4882a593Smuzhiyun {
27*4882a593Smuzhiyun 	if (macintosh_config->ident != MAC_MODEL_PB190) {
28*4882a593Smuzhiyun 		baboon = NULL;
29*4882a593Smuzhiyun 		baboon_present = 0;
30*4882a593Smuzhiyun 		return;
31*4882a593Smuzhiyun 	}
32*4882a593Smuzhiyun 
33*4882a593Smuzhiyun 	baboon = (struct baboon *) BABOON_BASE;
34*4882a593Smuzhiyun 	baboon_present = 1;
35*4882a593Smuzhiyun 
36*4882a593Smuzhiyun 	pr_debug("Baboon detected at %p\n", baboon);
37*4882a593Smuzhiyun }
38*4882a593Smuzhiyun 
39*4882a593Smuzhiyun /*
40*4882a593Smuzhiyun  * Baboon interrupt handler.
41*4882a593Smuzhiyun  * XXX how do you clear a pending IRQ? is it even necessary?
42*4882a593Smuzhiyun  */
43*4882a593Smuzhiyun 
baboon_irq(struct irq_desc * desc)44*4882a593Smuzhiyun static void baboon_irq(struct irq_desc *desc)
45*4882a593Smuzhiyun {
46*4882a593Smuzhiyun 	short events, irq_bit;
47*4882a593Smuzhiyun 	int irq_num;
48*4882a593Smuzhiyun 
49*4882a593Smuzhiyun 	events = baboon->mb_ifr & 0x07;
50*4882a593Smuzhiyun 	irq_num = IRQ_BABOON_0;
51*4882a593Smuzhiyun 	irq_bit = 1;
52*4882a593Smuzhiyun 	do {
53*4882a593Smuzhiyun 		if (events & irq_bit) {
54*4882a593Smuzhiyun 			events &= ~irq_bit;
55*4882a593Smuzhiyun 			generic_handle_irq(irq_num);
56*4882a593Smuzhiyun 		}
57*4882a593Smuzhiyun 		++irq_num;
58*4882a593Smuzhiyun 		irq_bit <<= 1;
59*4882a593Smuzhiyun 	} while (events);
60*4882a593Smuzhiyun }
61*4882a593Smuzhiyun 
62*4882a593Smuzhiyun /*
63*4882a593Smuzhiyun  * Register the Baboon interrupt dispatcher on nubus slot $C.
64*4882a593Smuzhiyun  */
65*4882a593Smuzhiyun 
baboon_register_interrupts(void)66*4882a593Smuzhiyun void __init baboon_register_interrupts(void)
67*4882a593Smuzhiyun {
68*4882a593Smuzhiyun 	irq_set_chained_handler(IRQ_NUBUS_C, baboon_irq);
69*4882a593Smuzhiyun }
70*4882a593Smuzhiyun 
71*4882a593Smuzhiyun /*
72*4882a593Smuzhiyun  * The means for masking individual Baboon interrupts remains a mystery.
73*4882a593Smuzhiyun  * However, since we only use the IDE IRQ, we can just enable/disable all
74*4882a593Smuzhiyun  * Baboon interrupts. If/when we handle more than one Baboon IRQ, we must
75*4882a593Smuzhiyun  * either figure out how to mask them individually or else implement the
76*4882a593Smuzhiyun  * same workaround that's used for NuBus slots (see nubus_disabled and
77*4882a593Smuzhiyun  * via_nubus_irq_shutdown).
78*4882a593Smuzhiyun  */
79*4882a593Smuzhiyun 
baboon_irq_enable(int irq)80*4882a593Smuzhiyun void baboon_irq_enable(int irq)
81*4882a593Smuzhiyun {
82*4882a593Smuzhiyun 	mac_irq_enable(irq_get_irq_data(IRQ_NUBUS_C));
83*4882a593Smuzhiyun }
84*4882a593Smuzhiyun 
baboon_irq_disable(int irq)85*4882a593Smuzhiyun void baboon_irq_disable(int irq)
86*4882a593Smuzhiyun {
87*4882a593Smuzhiyun 	mac_irq_disable(irq_get_irq_data(IRQ_NUBUS_C));
88*4882a593Smuzhiyun }
89